An orthopedic boot has two leg supports connected adjustably to a foot support via two joint assemblies. Each joint assembly has a securing panel, a connecting panel, a guide panel, two limiting members and two holding members. The securing panel is mounted securely on the foot support and has two engaging grooves each having engaging cavities. The connecting panel is mounted securely to one leg support and is pivotally connected to the securing panel. The limiting members has a resilient segment, an engaging pin and a locking tab. The engaging pin is mounted slidably in one of the engaging grooves, engages one of the engaging cavities and selectively abuts the connecting panel. The locking tab is spaced from a periphery of the guide panel to define a locking gap. The holding members are held respectively in the locking gaps and abut respectively against the locking tabs.
